Journal of South China University of Technology (Natural Science Edition) ›› 2011, Vol. 39 ›› Issue (6): 1-6.doi: 10.3969/j.issn.1000-565X.2011.06.001

• Mechanical Engineering •     Next Articles

Microtopographic Modeling of Three-Dimension Surfaces and Simulation of Flow Characteristics of Fluid in Microchannels

Wang Qing-hui  Zheng Xu  Pan Min-qiang  Li Jing-rong   

  1. School of Mechanical and Automotive Engineering∥Key Laboratory of Surface Functional Structure Manufacturing of Guangdong Higher Education Institutes,South China University of Technology,Guangzhou 510640,Guangdong,China
  • Received:2010-07-29 Revised:2011-01-04 Online:2011-06-25 Published:2011-05-06
  • Contact: 王清辉(1972-) ，男，教授，博士生导师，主要从事机械制造及自动化研究． E-mail:wqh@scut.edu.cn
  • About author:王清辉(1972-) ，男，教授，博士生导师，主要从事机械制造及自动化研究．
  • Supported by:

    国家自然科学基金资助项目( 50975092， 50805052) ; 广东省自然科学基金资助项目( 9151030101000007) ; 华南理工大学中央高校基本科研业务费专项基金资助项目( 2009ZZ0041)

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Abstract:

In order to implement the multiscale digital design of metal functional surface structures,a mathematical method combining the Weierstrass-Mandelbrot fractal geometry and the three-dimension parametric surface is developed based on the self-affine fractal characteristics of the microtopography of machined metal surfaces. With this method,the coarse microtopography of three-dimension structures can be well integrated with macroscopic models,so that a multiscale microtopographic model of functional surface structures can be established. For experimental investigation,a multiscale 3D solid model is created to simulate the flow characteristics of fluid in a ploughed Vshaped microchannel,and the influences of the Reynolds number,the surface height scale coefficient and the fractal dimension on the flow characteristics are analyzed. The results show that ( 1) the frictional resistance coefficient decreases with the increase in the Reynolds number,but increases with the surface height scale coefficient; ( 2) the influence of the fluid vortex due to surface roughness,which becomes significant with the roughness increase,is non-neglectable; and ( 3) the frictional resistance coefficient of microchannels decreases with the increase of the Weierstrass-Mandelbrot fractal dimension.

Key words: functional surface structure, fractal, microtopography, microchannel, flow characteristic